Conventionally, there was a writing device in which an alarm was attached. But this alarm was not for awakening the person from a sleeping state, but for indicating the fact that an appointed time or a preset time had arrived.
Generally, serious students who are immersed in ardent and assiduous studies may have difficulty in getting the proper amount of sleep for good health. A student who does not get enough sleep may tend to relax slightly and fall asleep while studying, dropping his pen at the same time. And once such a student falls asleep, his sleep is of a deep kind. In such a situation, his studies cannot be carried out at a predetermined schedule.